Minimally invasive or minimal access surgeries involve a modern technique in which operations inside the body are performed through small incisions. This technique is now being favored by surgeons over traditional open surgeries which require large incisions to gain access to the target surgical site. In addition to requiring larger incisions, traditional open surgeries require displacing a large amount of peripheral tissue to gain access to the target surgical site as well as a greater volume of blood loss for the patient. Thus, after traditional open surgeries, patients have to deal with a longer recuperation time, a greater degree of pain and scar. Minimally invasive or minimal access surgeries reduce these undesirable results of traditional open surgeries.
In minimally invasive surgical procedures, access to organs, tissue, and cavities inside the body is usually provided by inserting a cannula or other instruments through a small access hole. The initial access is usually created by piercing the skin and subcutaneous layers with a needle, a trocar, or both. Sometimes a series of dilators with increasingly larger diameters is used to enlarge a working channel for minimally invasive surgeries.
While minimally invasive surgeries have many advantages over traditional open surgeries, injuries to internal organs, tissues, blood vessels and nerves may occur during the initial step of blindly introducing a needle, trocar, dilator, or other instruments into the body. In fact, a vascular injury is a major cause of death from laparoscopy. The reason for a vascular injury is proximity of the abdominal wall to the retroperitoneal blood vessels, such as distal aorta and iliac artery and vein.
Thus, there is a need to improve minimally invasive or minimal access surgeries when an initial instrument, such as a needle, trocar, or dilator, is introduced into the body cavity. It would be desirable to have a monitoring system which allows a surgeon to determine if there are any vital organs or tissues, such as blood vessels or nerves, near the distal end of the initial instrument so that the damage to the organs and tissues can be avoided or minimized.
Embodiments of the invention meet this and other needs.